Daily non-zero values of snowfall and liquid water equivalent
within a given month were ratioed based on the entire length of record
for each station (which is variable between stations). An average was
then computed from the individual daily values to obtain a snow water
equivalent for each station. The ratios were then gridded using a kriging
technique. Higher ratios indicate wetter snow events (high liquid water
content) while lower ratios represent drier snow events (low liquid
water content). Quality control was performed to eliminate sources of
error, such as days with a mixed precipitation type (yielding anomalously
high ratio), or stations with very few daily observations.